Introduction: The health impacts of working in stone quarrying industry have been well documented. Inhalable dust is produced when the stone is cut and by the breaking of the stones on the quarry floor during the transit of the vehicles. A particular concern in some quarries is the inhalation of dust containing silica which can lead to silicosis. Workers exposed to high intensity of dust would have increased Tumour Necrosis Factor-Alpha (TNF-α) in serum which is a strong indicator in predicting the prognosis of pneumoconiosis. Aim of work: To find out the relation between serum levels of TNF-α and some spirometric parameters in workers exposed to stone dust during quarrying. Materials and Methods: Fifty five workers who were exposed to stone dust in quarrying industry participated in the study. A control group of 55 individuals were randomly selected to be matched with the exposed group as regards age, gender, and special habits of medical importance and not exposed to dust. Full medical history and clinical examination were carried out to all participants. Ventilatory function tests (FVC%, FEV1%, FEV1/FVC%, PEF%, FEF25%, FEF50% and FEF75%) and serum level of TNF-α were measured for both groups. Results: There were mild to moderate restrictive ventilatory impairment and mild obstructive impairment among the exposed group (statistically highly significant (p<0.001) when compared to the control . Serum levels of TNF-α were significantly higher among the exposed than the control group. Duration of exposure to dust negatively correlated with spirometric parameters and positively correlated with the serum level of TNF-α among the exposed group. Also the latter negatively correlated with spirometric parameters. Conclusion: Serum TNF-α can be used as a biomarker for detection and follow up of pneumoconiosis in workers exposed to stone dust in quarrying industry.